The present invention relates to a biometric authentication device and a method of the same, and in particularly to a biometric authentication technique to authenticate a biologic object by using a finger vein.
In these days, the biometric authentication technique has been taken notice of using inherent bodily characteristics of an individual, instead of conventionally using passwords, keys, personal stamps, etc. The biometric authentication technique has advantages such that risk is relatively low against theft, loss, unauthorized transfer, and oblivion, therefore, it has high security level.
In the various biometric authentication techniques, a finger vein authentication uses a finger vein pattern of a body's interior to realize an excellent authentication accuracy and a high level security, since a forgery or falsification is hard to be realized, compared with a fingerprint authentication.
If the above-mentioned authentication technique is applied to “a common front door locked and unlocked system” disclosed in JP-A-2003-129712, a user or human passes through a biometric authentication device installed at an entrance, and must subsequently pass through another biometric authentication device installed at a door of his/her residence.
In the meantime, there is a problem that the biometric authentication device cannot extract feature information, necessary for the authentication, caused by a reason such that some one has a fine finger vein.
Consequently, for a purpose of realizing that the above-mentioned person can be checked by the biometric authentication even though the human has the fine finger vein, it is conceivable that another authentication function is incorporated into the biometric authentication device. For example, JP-A-2006-251961 has disclosed a method in which a password authentication function is provided in a client server system having a biometric authentication function to thereby attempt to cover the human who cannot be checked by the biometric authentication.
Further, as for the authentication device that executes the human authentication at a gate, JP-A-2005-350960 has disclosed a system incorporated an IC card with the fingerprint authentication.
In addition, there arises a problem that a sensitivity of the biometric authentication device is made low to thereby deteriorate the security level, for a purpose of preventing the human from missing the biometric authentication. In the case of the existing biometric authentications, it is necessary to incorporate the existing authentication function, using the IC card, password, etc., into the biometric authentication technique, since the occurrence in which the human is not checked by the existing biometric authentication cannot be avoided, however it arises sometimes.
However, in the case of the above technique, there arises a problem that the advantage of the biometric authentication technique becomes impaired, even though the technique has high security level and excellent convenience as a substitute for the existing authentication technique, and the biometric authentication device becomes complicated, and the device cost becomes high.